Blog for the RepRap project at www.reprap.org - a project to create an open-source self-copying 3D printer.

Tuesday, March 08, 2011

Impartial reivew of the Clonedel Cast parts by Metrix Create Space

Open3DP was nice enough to send me some of the cast parts being sold by Metrix Create Space. I wanted to see the part quality in person, and to give them a impartial look.

I have seen the Techzone Lasercut wooden Mendel, the CNC milled Issac Mendel, and wanted to see if these cast parts where usable. I was very surprised at how strong they where and the their quality.

To use them you will need a drill press, and the parts are a bit weaker than ABS, but I think they seem usable.

Below is a video of a Mendel assembled with these parts printing a cube.

That's one of the issues with disruptive technology like RepRap, every time you think you have a handle on how things are going, it surprises you.

18 Months ago the plastic parts for a Mendel where going for $700+, 12 Months ago the price settled down to $250-$400, 3 Months Ago Prusa Mendel dropped the price for the RP parts to $125-$150. Now the Clonedel cast RP parts are going for $50 (I personally know of 3 shops gearing up to start selling them).

I just ordered a small drill press on sale from Harbor Freight for $50. At that price, the Clonedel set AND the drill press to finish them costs less than the printed parts.

And of course, while those look like they're plenty strong (with the flexibility, they might even be better than ABS), the cast parts only really need to last long enough to get the machine printing well enough to make its own spares.

I have had a few email exchanges with Mark Ganter from Open3DP and found him to be extremely helpful and knowledgeable. There seems to be so much great stuff going on with his group that I would really like to toss the whole "working for a living" thing and go back to university. Unfortunately my wife refuses to support an unemployed student. Shocking!

Neil, thank you for taking your time to work through a very fair review of the parts. Since, none of the parts on a Mendel or Clonedel are handling much more than about 10-20 lbs of loading, I believe they are more than adequate. If not, we can modify the parts OR pour them out of a stronger resin (as needed). Smooth-Cast 300 has a strength of about 4000 psi. Resins which are 7000 psi are readily available and some as high as 10000 psi. Brittleness is not a strength issue. It is a toughness issue. ABS is a very tough resin. A real interesting question: What are the engineering strength requirements for the Mendel/Prusa parts?

Not sure where you got your components from. Castings sounded like a great idea, but the casting quality of the components I received from Metrix Communication was absolute rubbish. 60 grit sandpaper is flatter than the surfaces (including the gear teeth, and nothing is square. even the 'flat' surfaces have defects and plateaux. The work required to fix the castings took about 3 hours, then the drilling another 2 hours. Be quite careful where you purchase from.